This is the first in a series of guest columns by Nancy Novak discussing important issues related to the sustainability of data center construction. This first column discusses how a holistic approach to data center sustainability must have a focus on water-friendly practices.
While a lot of effort has gone in to greening up data centers from an energy use standpoint, less attention is given to water even though, unlike energy, water lacks alternatives. This is a critical issue because water is an increasingly scarce resource globally. Worldwide water use has increased sixfold over the past 100 years as the global population and our interconnected economies have grown. That growth is continuing unabated, with water consumption projected to continue to increase by 1% every year. This ever-increasing demand for a finite resource will put a stronger spotlight on how water-intensive industries like the data center industry use water. And yet, there has been far less discussion of data center water usage than other aspects of sustainability.
Why the lack of focus on water?
For one, data centers have essentially become critical infrastructure. The pandemic elevated data centers from resource to utility as the world transitioned to working, learning, and streaming entertainment from home. There is intense demand for more data center capacity. Now doesn’t seem to be the time to slow down and rethink how data centers are designed and operated…or cooled.
There is also a matter of perception. Water is mistakenly perceived to be plentiful. It falls from the sky, after all. And more than 70% of the earth’s surface is covered in it. But of course, we know much of that water is inaccessible or unusable, leaving us facing a global water shortage. In fact, the UN encourages countries and regions to be proactive in treating water as a scarce resource.
Unfortunately, most data centers today are not built to conserve this resource. The Department of Energy estimates that the average data center consumes 1.8 liters of water to cool every kWh it consumes, while some industry experts estimate a higher volume of around 5 liters/kWh. Using the lower estimate of 1.8 liters/kW, a 30MW datacenters will consume 1.3 million liters/day or 343,000 gallons/day. To put it in perspective, the average consumer uses about 80-100 gallons of water/day, or 142 liters in the UK. As an industry, we need to do better.
Moving Toward Sustainable Water Use
While less focus has been placed on water compared to power use for sustainability, there is movement in the right direction. Sustainable water strategies include both sourcing and design. On the sourcing front, some hyperscale facilities are starting to include on-site water treatment facilities to tap into local, non-potable water sources. In places like Singapore, non-potable water usage is mandated for water cooled systems. Local municipalities have also put a cap on the amount of fresh water that can be consumed by a datacenter facility.
On the design front, more and more providers are choosing cooling systems with minimal need for water. Others are incorporating rainwater recovery strategies to capture rain, store it on site and use it for cooling to reduce burden on local water supplies.
A redesign is no small undertaking. Replicability in data center design makes it possible to build them quickly and affordably. Deviating from a design plan or retrofitting has trickle down effects into the supply chain which make it a major undertaking. All to say, design shifts will evolve slowly.
Since its inception, Compass has used a waterless airside cooling design. Free and 100 per cent renewable, air is drawn into the facility through finely calibrated filters (to remove particulates) and used to cool the facility. While certain areas of the country have more free cooling hours than others, there is virtually nowhere in the country where it can’t be used. Even Houston, Texas provides over 3,600 hours of free cooling annually. Thus, Compass Datacenters can operate in even the most drought-stricken areas of the country.
The pivot toward more water-friendly solutions comes as water availability is a major concern in the context of climate change. In the same way that minimizing power use and investing in renewables gained focus and importance over the last decade, we’re pivoting to develop solutions to minimize the industry’s impact on water. New KPIs such as Water Usage Effectiveness and Carbon Usage Effectiveness are becoming the driving force for datacenter designs and selection. Adopting these metrics as part of a stronger focus on sustainable water consumption is an important step for our industry. It is an important step in the right direction and will hopefully make water-friendly practices a part of every company’s data center sustainability plan.
About the Author
With more than 30 years of experience in the construction industry, Nancy Novak brings extensive expertise in oversight and responsibility for Profit and Loss. In her current role as Chief Innovation Officer for Compass Datacenters, her focus is cutting edge technology, lean practices, and innovative culture through diversity of thought to add value, improve return on investment, and disrupt the construction industry. She is heavily involved in organizations that lead the way for technological advancement in the construction industry, and she is an advocate for women’s leadership. Nancy currently serves as the Board of Director Vice Chair on the National Institute of Building Sciences BIM Council, as well as Executive Sponsor for the Digital Divide on the iMasons Advisory Board. She is also the host of the “Breaking Glass” podcast, which features Nancy’s dynamic conversations with prominent women in the technology industry – a forum where these accomplished women offer insights, advice and inspiration that listeners can apply to their own professional lives.